Numerous lock constructions have been developed and are widely employed by individuals to prevent unauthorized persons from gaining access to any area which has been closed and locked. Although many locks are constructed to be opened by a key, numerous combination locks have been developed which are opened by knowledge of a particular combination.
One particular type of combination lock that has become very popular due to its ease and convenience of use is a combination lock which employs a plurality of rotatable independent dials, each of which forms one of the indicia, usually numerals or letters, comprising the combination for releasing the lock. Typically, the combination lock has one mode or position in which the user is able to set or reset the desired combination sequence. Although locks of this general nature have been available for several decades, these prior art combination lock constructions suffer from common deficiencies which have not been successfully overcome.
Although many manufacturers have attempted to solve the problems associated with rotatable dial or combination locks, these prior art constructions have been unable to produce a construction which provides a unique visual display or indicator to the user when the lock is in its combination set or reset position. As a result, combinations can be accidentally or inadvertently changed without the user becoming aware of the new combination.
In addition, another problem prior art combination locks have been unable to provide is a construction which eliminates the ability of unauthorized persons discovering the combination for opening the lock. Although numerous attempts have been made in prior art constructions for achieving a system which would eliminate or prevent these problems, these prior art constructions have failed to provide the desired results.
Another common problem which has consistently plagued prior art constructions is the cost of construction for producing and assembling prior art combination locks. In order to attain a combination lock which provides all of the features desired by consumers, prior art constructions typically incorporate numerous small components, each of which require expensive assembly procedures to produce the final product. As a result, these prior art lock constructions typically are expensive to produce, thereby reducing the ability of these locks to reach a broad base of consumers.
Another problem commonly found with prior art combination locks is the inability of these prior art constructions to prevent contaminants from reaching the rotatable, internal components of the lock, thereby causing damage to these components or interfering with the ease of operating the lock by an individual knowing the actual combination. Although numerous attempts have been made to reduce the adverse effects caused by contaminants reaching these components, such attempts have been incapable of satisfactorily eliminating this problem.
Therefore, it is a principal object of the present invention to provide a combination lock construction which provides an automatically generated, positive visual indicator whenever the lock is placed in its combination set or re-set position.
Another object of the present invention is to provide a combination lock construction having the characteristic features described above which virtually eliminates the ability of unauthorized persons from gaining access to the lock by attempting to pick the lock using known techniques.
Another object of the present invention is to provide a combination lock construction having the characteristic features described above wherein the visual indicator remains displayed throughout the combination setting/re-setting function, disappearing only when the user has successfully completed the setting function.
Another object of the present invention is to provide a combination lock construction having the characteristic features described above wherein the visual indicator is prominently displayed in an easily seen and readily recognized manner.
Another object of the present invention is to provide a combination lock having the characteristic features described above which employs a minimum of components and is quickly and easily assembled, thereby providing a lock capable of being constructed at a competitive price.
Another object of the present invention is to provide a combination lock construction having the characteristic features described above which effectively seals the rotating components from external contamination and effectively prevents any external contaminants from reaching the rotating components thereof.
Other and more specific objects will in part be obvious and will in part appear hereinafter.